I had a bit of a play around with mapping the voter return data from the 2016 Auckland local body elections (raw data available here). I looked at it two ways:

What areas had the highest/lowest turnout? (i.e. where is participation high/low)

What areas had the highest raw number of votes? (“who elects the mayor”)

Maps addressing these two questions are below. Note that they don’t include Waiheke, mainly because it’s not part of the “Coastlines” shapefile I used to crop the board boundaries and I decided the effort of separately mapping the board area to the “islands” geographic shapefile wasn’t worth the effort given I have a day job (i.e. I am lazy). If you are wondering, turnout on Waiheke was very high (58.6%).